I was looking at the code last night, and I wanted to add a line that if the To: field contains, for example 'User' instead of 'User@domain.com', the '@domain.com' part gets added internally.
This would make it somewhat easier/faster to send internal emails from members to other members.
If someone could post the additional lines for this, that would be great. I could probably figure it out myself, but it would take awhile.